Recent insights into the neurobiology of interstitial cystitis (IC) and into mechanisms of visceral pain suggest that, like other visceral pain syndromes, IC may be associated with hyperalgesia of the bladder itself, and central sensitization of pain pathways from the bladder. There also may be increased sensitivity to stimulation of body wall tissues in dermatomes to which bladder pain refers. Advances in our understanding of bladder hyperalgesia to distension and the presence of such altered cutaneous stimulation thresholds will help us to design more elegant and evidence-based treatments for IC. This proposal first describes a simple study to measure sensory aspects of bladder sensation with filling in subjects with IC and in controls. Secondly, the use of a Neurometer as a simple instrument to measure cutaneous thresholds to stimulation at frequencies of 2000Hz, 250 Hz, and 5 Hz is described. Finally, testing for the presence of temporal summation of pain and bladder filling sensations as a measure of centralized sensitization of pain pathways is described. If the results of this psychophysical testing prove to be significantly altered in subjects with IC, simple clinical testing of pelvic referral dermatomes may allow clinicians to assess patients for central sensitization, then design and evaluate treatments accordingly.